Fungi in the genus Pneumocystis live in the lungs of mammals, where they can cause a fatal pneumonia (PCP [Pneumocystis pneumonia]) in hosts with compromised immune systems. The absence of a continuous in vitro culture system for any species of Pneumocystis has led to limited understanding of these fungi, especially for the discovery of new therapies. We recently reported that Pneumocystis cari...

Pneumocystosis-related surfactant changes have been reported in both humans and corticosteroid-treated experimental hosts. As corticosteroids induce an increase in pulmonary surfactant, some findings could be considered as controversial. The aim of this study was to investigate whether the surfactant composition changes during experimental pneumocystosis were related to the Pneumocystis develop...

BACKGROUND Infection with Pneumocystis carinii typically results in a pneumonia which histologically is seen to consist of an eosinophilic foamy alveolar exudate associated with a mild plasma cell interstitial infiltrate. Special stains show that cysts of P carinii lie within the alveolar exudate. Atypical histological appearances may occasionally be seen, including a granulomatous pneumonia an...

Analysis of the Pneumocystis murina MSG gene family and expression-site locus showed that, as in Pneumocystis carinii, P. murina MSG genes are arranged in head-to-tail tandem arrays located on multiple chromosomes, and that a variety of MSG genes can reside at the unique P. murina expression site. Located between the P. murina expression site and attached MSG gene is a block of 132 basepairs th...

The mode of Pneumocystis carinii transmission is controversial. Recent studies point to exogenous inoculation rather than reactivation, and person-to-person transmission has also been suggested. Comparison of nucleotide sequences of the large-subunit mitochondrial rRNA gene of P. carinii from human immunodeficiency virus-seropositive patients showed strain differences.

Pleura-based masses and hilar adenopathy were seen on a chest radiograph of a patient with acquired immunodeficiency syndrome who had a history of Pneumocystis carinii infection. The differential diagnosis of such a presentation is discussed in light of atypical and extrapulmonary manifestations of P. carinii infection in a patient receiving prophylaxis with dapsone.

An infant infected with HIV presented with fever, tachypnoea, hypoxia, and radiological evidence of bilateral pneumonitis. Fluorescent antibody technique identified Pneumocystis carinii within 24 hours from secretions obtained by nasopharyngeal aspiration. This rapid, non-invasive method should be the first line investigation of suspected P carinii pneumonia in immunocompromised patients.

We compared the prophylactic activities of six fluoroquinolones against Pneumocystis carinii pneumonia in immunosuppressed rats. Pefloxacin was the only agent which was as effective as the reference drug trimethoprim-sulfamethoxazole. Clinical trials with pefloxacin in patients at risk for P. carinii pneumonia appear to be justified.

Failure of sulfa or sulfone prophylaxis is associated with mutations in Pneumocystis carinii gene coding for dihydropteroate synthase (DHPS). The DHPS genotype was analyzed in AIDS patients who had two separate episodes of P. carinii pneumonia. The results suggest that DHPS mutations can be selected de novo within patients by the pressure of a sulfa or sulfone drug.

Pneumocystis pneumonia is considered one of the most serious fungal respiratory infections in immunocompromised patients and animals. Molecular comparisons of various gene sequences clearly demonstrated that the single name P. carinii corresponds in fact to a complex group of eukaryotic organisms, which should be assigned to the kingdom Fungi (Edman et al., 1988; Stringer, 1996; AliouatDenis et...